Committing genocide against the Kett is a must?

We all know damn well Bioware won't go there. They are interested in telling their story and we get to roleplay within the confines of that. They want to paint humanity as the morally superior species, and that's hard to do if if you're slaughtering entire species. Besides Bioware just isn't good at handling "morally grey" or highly controversial material. They're very risk averse. Besides they've already stated we're in Andromeda as explorers, not conquerors. And really it would be hard to conquer a hundred solar system area of a galaxy with a few hundred thousand members of the various races unless the races we encounter are technologically challenged. So no, sorry, you won't be seeing any subjugation/annihilation of species in MEA.

Wilson was during WW1. I think you mean teddy rosevelt or anyone from 1944 on in american politics.

I'd say "never outright evil on a large scale" I'd say that there's a lot of options in Bioware games that are outright evil, even if they don't have the impact of wiping out a race just to establish your domininance. Always keeping in mind that  there's always (att least some) grey areas in what it's evil and what it's not, of course, there's a lot of things that I can only bring myself to do in an evil pt, and even so there's still some that I just can't do, period.

To be fair the western powers like england did that ALOT in the days of the british empire and the spanish did it in mexico. Just use their tactics side with one and use them to destroy the rest or weaken them to the point you can just walk over and plant a flag on a mountain of dead bodies. Cortez had three hundred people and took over mexico. He used the people who hated the aztecs to fight them and one. The british did this in india as well and so on and so on.

Under Walters we had the options to annihilate geth ⎌ and quarians, to once again kill the rachni for good, and again kill all geth and EDI in Destroy. I don't see why Walters would be a problem for that.